Scanner


1   /*
2    * Scanner.java
3    *
4    * Created on April 12, 2005, 8:05 PM
5    */
6   
7   package org.netbeans.modules.piaget.analyze;
8   
9   import java.io.InputStreamReader  ;
10  import java.io.IOException  ;
11  
12  
13  /**
14   *
15   * @author loicsegapelli
16   *
17   * Opens a file and gets content as tokens.
18   */
19  class Scanner {
20  
21      public static final int EOF = -1;
22      public static final int WORD = 1;
23      public static final int LONG = 2;
24      public int lastReturned;
25      
26      /** This character represents the end of the input.
27       */
28      private static final char EOF_CH = (char)-1;
29  
30      private boolean pushed;
31  
32      //protected int start;
33  
34      public String   sval;
35      public long lval;
36  
37      private StringBuffer   buf;
38  
39      /** The current character.
40       */
41      private char ch;
42  
43      private int line = 1;
44  
45  
46      
47      /** The input stream providing the input characters.
48       */
49      private final InputStreamReader   in;
50  
51      public Scanner(InputStreamReader   in) {
52          this.in = in;
53          pushed = false;
54          nextCh();
55      }
56  
57      /** close the file input stream
58       */
59      public void close() throws IOException   {
60          in.close();
61      }
62      
63      public void pushBack(){
64          pushed = true;
65      }
66  
67  
68      public int nextToken() {
69          if(pushed){
70              pushed = false;
71              return lastReturned;
72          }
73          
74          buf = new StringBuffer  ();
75          while (!interestingChar()) nextCh();
76          if(ch == EOF_CH) return EOF;
77          while(interestingChar()){
78              buf.append(ch);
79              nextCh();
80          }
81          
82          if(buf.length() == 0){
83              nextToken();
84          }
85          
86          
87          String   result = buf.toString();
88          
89          try{
90              long l = Long.parseLong(result);
91              lval = l;
92              lastReturned = LONG;
93              return lastReturned;
94          }catch (NumberFormatException   e){
95              sval = result;
96              lastReturned = WORD;
97              return lastReturned;
98          }
99          
100     }
101     
102     private boolean interestingChar(){
103         return ch != '\n' && ch != '\r' && ch !='\t' && !Character.isWhitespace(ch);
104     }
105 
106     public int lineno(){
107         return line;
108     }
109     
110     /** Puts the next character into 'ch' and updates the current position.
111      */
112     private void nextCh() {
113         switch (ch) {
114             case EOF_CH:
115                 return;
116             case '\n':
117                 line++;
118                 break;
119             default:
120                 break;
121         }
122         try {
123             ch = (char)in.read();
124             oldch = ((oldch == '\r') && (ch == '\n')) ? (char)in.read() : ch;
125             ch = (oldch == '\r') ? '\n' : oldch;
126         } catch (IOException   e) {
127             e.printStackTrace(System.out);
128         }
129     }
130 
131     private char oldch;
132 }
133
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